I know that support is going to be limited on this since it doesn't directly involve your theme... but I'm hoping for a little help here.
I came across a site tonight that tells how to quickly and easily add a Twitter share button and Facebook like and send buttons onto your wordpress site. You insert their PHP file into your main theme folder, add a call line into the theme's functions.php file, and then insert a shortcode into the sidebar. Problem is, I don't think this file is getting called properly in the functions.php file because the shortcode is just being displayed as text in the sidebar.
I have tested this with three other themes though and it works flawlessly. I'm only having trouble with Avisio. I think there's something weird/different with the way the functions.php file of this theme works. Any help would be greatly appreciated. Here's a link to the site with the instructions and the file: http://digitalraindrops.net/2011/04/facebook-like-and-send/